1. Technical Field
The present invention relates to a light-emitting element module, an atomic oscillator, and an electronic apparatus.
2. Related Art
There are known light-emitting element modules that adjust temperatures of the light-emitting elements using Peltier devices (for example, see JP-A-7-104332). A laser light-emitting device which is disclosed in JP-A-7-104332 and is an example of the light-emitting element module includes a semiconductor laser element (light-emitting element) and an electronic thermo-element (Peltier device) using the Peltier effect and a package accommodating them. Here, the semiconductor laser element is mounted on the inner surface of the package via the electronic thermo-element. Then, temperature of the semiconductor laser element is adjusted by the electronic thermo-element. Light from the semiconductor laser element is output outside via a window installed in the package.
In the laser light-emitting device disclosed in JP-A-7-104332, when ambient temperature becomes high, the temperature of the entire package is considerably increased. Thus, the temperature of the semiconductor laser element is varied due to radiation of heat from the package. Accordingly, there is a problem that the wavelength of light from the semiconductor laser element may vary.
Here, when the external temperature of the package is higher than a target temperature of the semiconductor laser element, the temperature of a wall surface side of the package of the electronic thermo-element becomes high, and thus the package is heated. In the related art, since a heat dissipation property of the package is bad, the temperature of the package is considerably high with respect to the temperature of the semiconductor laser element. As a result, the above-described problem arises.